function mymodule_form_alter(&$form,$form_state,$form_id){switch($form_id){case'mymodule_settings_form':// get a reference to the checkboxes form element$form_elem=&$form['settings']['options'];// replace the element with its expanded items$form_elem= expand_checkboxes($form_elem);// get the child elements$items= element_children($form_elem);// modify the child elementsforeach($itemsas$item_key){// get a reference to the child element$elem=&$form_elem[$item_key];// customize the child element$elem['#description']= t('Description of @elem_title',array('@elem_title'=>$elem['#title']));}break;}}